If you just want to make fellow cachers angry, just put a tub of night crawlers in the ammo can with the log (they actually melt in the heat!). Or put a micro inside an animal corpse.
Also, for a variation on the river theme, use alternating north and southbound rest areas on a highway. Make that a PAY highway. And if you're going to use dead end coordinates, don't put a capsule saying 'dead end'. Just keep them guessing as to whether or not they missed it.
All that said, I like a good, old fashioned 2-3 diff ammo can better than those micos. Tink-tink