Last semester I took a textiles class and we did 3 weeks of lab study on stain removal. These were the results.
Detergent info from my Textiles class.
Stain removal:
Tannin stains (fruit, vegetables, coffee, tea)
Removal pour boiling water from a distance and use a general purpose detergent.
Protein stains (dirt, blood, egg, meat)
Removal soak in cold water for 20-30 minutes and use an enzyme detergent (Biz)
Grease/Oil
Removal rub general purpose liquid detergent on both the front and back, let the stain absorb the detergent for 10 minutes, scrub briefly between fingers and repeat until gone.
Permanent Dyes (grass, ink, dye)
Removal start immediately, general purpose liquid detergent, no waiting, scrub, repeat, chlorine bleach unless it will damage the color of the fabric.
Ball point ink
Removal soak in alcohol for 10 minutes scrub, general purpose liquid detergent coat fabric scrub.
Rust
Removal lemon juice and salt, also RIT color removal
Combination stain
Work on the stain first that is most difficult to get out
Hope this helps!