I run:
Mains: Bomb Range Up (Pilot Goggles), Special Charge Up (Orange Cardigan), Ink Recovery Up (Green Hi-Tops)
Subs: Special Duration Up x3 (Pilot Goggles), Ink Saver Main x3 (Orange Cardigan), Swim Speed Up x 3 (Green Hi-Tops)
I actually run this set with pretty much anything with bombs, but it works for the Tri-Slosher
Bomb Range up is pretty useful for tagging snipers or far-off foes with Disruptors so they can't approach you, you might want to try that out. The Special affecting abilities are there because the Bubbler is dynamite, and you want it charged up as fast as possible, so maybe try those, too.
Keep moving with the Tri-Slosher, it's way more mobile than the regular Slosher and is thus less defensive. Bob and weave, flank and splat.