Based in elgin, moray, ums ltd is a specialist drains and cctv survey company offering a wide range of services to suit the commercial and residential sectors. I) a 2-day course in water service works, and pass a writtten examination conducted by pub. I tried baking soda/vinegar the other nite - the clog got worse! i still haven't been able to use my shower maybe i didn't use enough of something? or maybe the standing water in the tub diluted it too much? i'll try soda in a minute... You may be.