I keep reading about or watching videos with people using fully skirted jigs with trailers in vegetation.

 

I own a couple but am reluctant to use them as my locals are like jungles with heavy submerged vegetation.

 

Any advice, thoughts suggestions?

If you're pitching in holes of vegetation a 1/2 works nicely, try to be as vertical as possible with your presentation. A heavy weedguard and hook is necessary which means a heavy rod with heavy line is needed as well. I haven't ever punched a jig through vegetation so would suggest a punch rig or jika rig for that. 

An actual mop jig is a little different than what it sounds like what you're talking about. They're more for fishing slowly to allow the big skirt to flare out and attract the fish's attention. A regular skirted jig will work just fine in weeds though. Best of both worlds is a punch rig or slither rig though.