"Heavy ammo glitch" is the only class to solo HM Crota :-/
The Titan and Warlock strats are virtually identical, they just get their two DoT grenades from a different class-specific ability and add it to the GHorn spam. If Bungie didn't nerf I-WoL + GHorn for no valid game design reason, Titans would easily be the best solo class. Not sure if the math would work exactly, but the 35% damage buff would basically offset the 32% damage penalty for being under-leveled and two Horns should still take his shield down.
But honestly I really do like playing as Warlocks, 1 character per class is the only way for me. I enjoy the variety so much.
What time would you be doing those? Seeing as how it's also the only stuff left for me as well, haha. Honesty don't care about HM abyss-bridge but it's fun with a team.