Conditions vary between clubs with some requiring up to 100hr P1, I know some small clubs wouldn't mind an ad-hoc extra volunteer tug pilot but most clubs, especially the bigger ones rightly require gliding experience to at least a solo standard, if not closer to cross country standard so the pilots know what they're doing.
As such, I know for a fact that applicants have been turned down for positions due to a lack of gliding experience.
But if you're already involved or happy to get involved with flying gliders there's great opportunities available, I know one chap who got the vast majority of his hours for CPL for free and got accommodation and some food included too. Did help he started Gliding in his teens though!
Banner towing could be a possibility but I know very few operations like that.
Best of luck.