Thats what I spend most all of my time doing in summer/ fall once hydrilla gets up. Theres plenty of swimbaits that will work. Just need a bait that sinks slow enough that it will not hang up before you start your retreive. The bait will also have to hold up to the hydrilla once a fish gets down in it. If the bait has any breakage problems (weak hooks, rings, or construction) at all don't get it or you will lose fish on it and break the bait. Theres a ton of baits out there that will break trying to get a fish out of hydrilla. Also look for baits that don't roll over at the surface at high speeds. Hydrilla flats can be covered better at times with fast swimbaits and all day topwater strikes are common in summer as fast as you could ever reel the swimbait.
Once the grass gets to the surface and treble hook and top hook baits are hanging up go to baits like the hollow body swimbaits, Mission fish, weedless Hudds/ Grass minnows and the Lake Fork weedless swimbaits. I don't go to them first because of the hookup ratios are not as good but somtimes when the stuff gets thick you have no choice.