They are basically the same and they work best in warm water. Its like trying to wash your dishes in cold water, the oils and gunk dont come off as well. It should also run through the system for a period of time, if the tub is older, I would say 24 hours. It may be worth the wait.
These products do cause foaming. The best thing to do is after you drain, rinse well with water, put the hose right into the filter and flush that water out too. Drain this off then use a shop vac to suck water out of the lines. Put the vac on the end of each jet and get as much of the water out as possible.