Good vs. deodorant stains

The Vorwaschspray has well helped reduce my deodorant stains that have occurred since I switched to a deodorant with no aluminum. With the newer T-Shirts everything went out, in an older, it is much weaker. Could the next wash cycle all go out. If not, then I test soak it overnight in soda.

I've just sprayed on both sides prior to washing and then max. Waiting 5-10 minutes.
You do so but already quite a lot of it.
Then without it wash directly into the washing machine, normal washing with it.
I'll test it for some time and also compare with the powder, possibly It's so effective.