Yeah, no.
It's rebuild time. No band-aid will make things better. The solenoid probably isn't "bad", but full of crud. Like the rest of the trans is. I would guess the frictions were shot, which started the initial slipping. Lucasing it just stopped the slipping for a while, but didn't address the issue, and now all the shot clutch material is happily clogging the trans to death...like the solenoids... I just got done rebuilding mine, and it was a Complete PITA.
Have Dave at Triple ship you a new one.