A chicken drinker seems to be a device for ensuring that chickens get enough to drink (like a chicken feeder, but for water).
The way I approach keyword mining is to throw even what little I might know about a subject out of the window (not that I know anything about chicken rearing, I mean in general) and start from ecommerce sites, then GKT and then iterate on Google product search, etc... and just see where I get taken. The combined expertise of "everyone else in the world" will outweigh mine every single time, so I prefer to start from what others are selling/promoting as their business, rather than trying to second-guess by inserting my own keywords.
I've also found that Wikipedia can be quite a good source of keyphrases - for example, on a lot of topics they have sections dedicated to "tools for X" or "machines for X" or similar.
I only bother to "Whois" stuff with a decent amount of searches, and I do the Whois checking in bulk a few dozen names at a time using Watch My Domains Pro.
In a few hours, it's possible to turn up quite a lot of goodies if you stay focused, or at least that's what my experience has been. The above list for instance is just from stuff I found today. Some have tens of thousands of exacts, some have just a few dozen... but the latter's for plurals where the singular gets decent numbers - usually I find there's an artificial boost for the singular because that's what Google Suggest spits out when you start typing in the query, and besides I figure that a company actually making/selling product X thinks in terms of "more than one product X".
Likewise, I'll generally get plural and singular together if both are available, even if one gets great searches and the other gets practically none - it slams the door on somebody picking up the "almost as good" domain for regfee down the road.
Big tip: Google Keyword Tool is a very blunt instrument - don't make the mistake of thinking it's showing you THE highest results for a particular search phrase. Over thousands of searches, I've come to the conclusion that it tries to show a representative spread of fairly high searches, but it will miss things again and again, so you have to "seed" it with all kinds of variations on the initial search phrase.
For instance, if you're considering "lathe" and "lathes" (which I did for a while today) and you set it to UK English results, Exact Match, you will find that it won't show things like "capstan lathe" at all. But if you check "capstan lathe" you get 2,400 exacts. Hmmm. So where did I find "capstan lathe"? Off of a product list on one of the several lathe-related ecommerce sites I looked into.
I would guesstimate that 80%+ of the time, the nice names that I'm finding are still available are hidden in these kind of "blind spots" where a search on the wide keyword or keyphrase simply doesn't turn up that result amongst the top searches. Hence the need for the alternative approach. I love it when I find a rich niche (products selling for hundreds or thousands of pounds each) where the exact match names are all still available because it was hidden in a GKT "shadow" area.
Big tip #2: A lateral way to ferret out interesting keywords is to sit in front of the Google search box and start typing the first keyword of the 2 or 3 keyword expression you're interested in. For instance, if I wanted to find all kinds of interesting domains of the form "steel something" I would enter "steel" and immediately Google starts popping up suggestions.
But here's where the cunning bit comes in. If you then type " a" you'll see the top results for "steel a*" i.e. for two word expressions where the first word is "steel" and the second word begins with "a". Jot down any that look interesting, then delete the "a" and replace it with a "b" and you'll get all the expressions which start with "steel b*". And so on through to "z", which gives you a maximum of 260 results but in reality may leave you with 30-40 "interesting enough" keyphrases to then plug into GKT to start looking at number of searches, CPC bids, ad competition etc.
You can also use the cursor key to move to the beginning of the line i.e. just in front of the "s" of "steel" and type an "a" and you'll see all the suggestions that are "a* steel" i.e. two (or more) word keyphrases where the first word begins with an "a". That will give you another 260 possible results to mull over.
Hope this helps... Good hunting!