Bouncing isn't possible... Unless you can soc an item that makes you bounce off it like it's a monitor, but doesn't give you anything. Then you can make it your thokitem and you can have something similar to a bouncing attack, but not exactly. Don't use homing, as then you'll go in random directions when you thok. Multithok can be used here without it being overpowered, too.
Messing with thokitems can produce interesting results. I once made 200s spawn when you thok. Good fun. I've also made slingitem as a flicky, that was pointless but funny. I actually made a wad that spawns flickies when you thok, spin or shoot a ring. It also had homing thok. I'll try and dig it up for you if you want.