Nothing cleans a bathtub like 1:1 blue dawn and hot vinegar. Swish together in a spray bottle, spray the tub and let it sit for a few minutes to a few hours. Wipe with a rag and rinse.
Scrubbing Bubbles doesn't even come close to working as well.
MrsDrewsky said:We do this as well. Although we mix equal parts in one of those sponge scrubbers with the handle dispenser and leave it in the shower. That way when you're taking a shower you can scrub a little bit at a time. Our shower has been super spotless since. It's awesome. Make sure you have a non-skid mat in your shower though.