Banana stains can be surprisingly stubborn. Like almost all stains, acting quickly can help to get the best result. The worst thing that you can do, is to let the banana stain dry before trying to tackle it. Removing banana stains from a carpet is easiest when you have a commercial stain removing agent to hand.
Commercial Spot Remover
First blot the stain with a commercial spot remover such as a “stain devil”. Pour fluid onto a cloth rather than directly onto the carpet and blot the stain. Rinse the area thoroughly with water and then dry the area off with some absorbent material.
If you have to go out and purchase spot remover and are expecting it to take a while, gently moistening the stain to stop it drying out might help. Don’t add too much moisture though as y ou don’t want the stain to spread.
If the stain persists, try the dishwashing detergent solution described in the removing alcohol stains from a carpet section. Then rinse with warm water.