Commercial stain removers are often full of harsh chemicals. I like to use the following methods to get rid of stains (and even mould) from fabric as an alternative.
With most stains soaking the item in cold water for a couple of hours (or even better overnight) with 2-3 tbsp of the stain remover below is really effective. DO NOT use hot water or it may “set” the stain - (another one of my granny’s saying) .
Sometimes though that is just not enough and in which case I would recommend making up the following an applying it to the stain. (I would recommend you do a patch test if spraying the stain remover directly onto the fabric first by spraying onto a hidden area of your garment)
STAIN REMOVER SPRAY
3-5 drops of lavender or tea tree oil
225 ml (1 cup) of distilled white vinegar
125g (half a cup) of bicarbonate of soda
Combine all the ingredients in a spray bottle. Lightly dampen the fabric and then spray the stain. Gently scrub area with a toothbrush (sprinkle over half a teaspoon of table salt whilst you scrub if it’s a really stubborn stain) and then leave for an hour.
When the time’s up, wash the garment in your machine with your chosen detergent and stain should be gone.
Ps drying your washing outside on a sunny day is a really good way of whitening your whites. The sun's ultraviolet rays can cause colorful clothes to fade (I hang my my coloured clothes to dry inside out on a really sunny day), but they also brighten white laundry.