I can.
Invisible stickies, proximity mines, a sticky mine shotgun that fires all your loaded stickies at one time, and this is all just alternates of the one weapon!
Maybe grenades that explode on first impact instead of bounce, some form of smoke or gas grenade, a corrosive grenade that degenerates a sentry over time, something along the lines of an EMP grenade that would deactivate the sentry for a short amount of time.
For the bottle... I dunno, maybe a magnum-sized bottle (double damage, halved swing speed), maybe the first hit covers 'em in that toxic hellbrew he drinks, and the pyro's flame burns hotter.
Just off the top of my head.