Hn, thats an idea. Gauntlets with directional explosive seals slapped on. And a puppet style mechanism that automatically swaps in new seals after each strike! That would possibly be a way to eliminate the strength requirements for a Taijutsu style.
Using explosives in melee would be hilarious but I'm a bit dubious how it would work.
Lets make an assumption and say that we can make an explosion that starts by going in to one direction and doesn't exert force back in to the gauntlet. Even in this case the explosion is not really safe for us since the shockwave will propagate through air and mess us up almost as badly as the intended target.
The way it would work is if the "explosion" seal worked more like a storage seal that opens a portal and then ejects shrapnel (or whatever payload you want) in one direction without exerting force back towards the gauntlet. It would look pretty much the same but it wouldn't nearly as lethal for the user.
In short term we are better off supplementing our taijutsu with something like flashbang seals if we can device a good way to make ourselves immune to the effect, even for a short while. Maybe glasses that have seals that block extreme light for a half a second when activated? Earplugs that would do the same but with sound? Even one of those would give us a huge edge in combat.
A seal that muffles sound would also be great for stealth. Put them on your feet and you could run without making the slightest noise. Or maybe that's something ninjas can already do well with chakra, who knows.
But really, our explosive seals will be way bigger boon for Keiko and her kunais in direct combat than us. It's hard to make a guy explode if you are standing right next to them. Unless you are a water clone. We could put explosive seals inside a really thin cast iron shell, maybe add some padding for buyoancy, and stick them inside Nobby's clones. Explosive hugs for everyone! :lol