Stain remover? ...

Surprising my mom by doing laundry...?
several things can be used, solution oxy-clean, works well applied direct to the stain but you enjoy to be careful on colored material. It can also be added to the wash and help that way. For whites vinegar and bakingsoda work or the clorox bleach pen. I enjoy also used meangreen on stains and it works really well on hearth rug, but again have to experiment those color fabrics

How do you bring spray paint sour hand?
The best one out there is Shout It Out

or if you hold 98 ONLY STORE buy the Stain Be Gone

this one work very all right for me on stain for half the cost.
Shrink merino & lambswool sweaters?
Answers:    Yes, there are stain removers. What do you want to know roughly speaking them?

Please expand your question and I am sure someone will be glad to aid you out.