12 oz. white vinegar
12 oz. liquid, blue dawn detergent
Heat vinegar in microwave or in a pan until hot, pour into squirt bottle.
add the Dawn soap. Put the lid on gently shake to incorporate. Heating the vinegar causes the ingredients to mix better.
You have a powerful cleaning product that will melt soap scum for tub and shower buildup. clean sinks, appliance just about anything. spray mixture on allow it to sit as long as overnight if needed. then scrub and rinse.. Be careful because a little bit goes a long way. You need a 24 oz squirt/spray bottle.
Also you can remove lite soap scum by sprinkling a few drops of water on a used fabric sheet and using the fabric softener sheet to scrub with.