Purple spray is what every chicken keeper should have in their medical supply. Ours is purple spray plus aloe to soothe as well as disinfect.
Use the spray as an antiseptic as it contains Chorhexidine Gluconate which helps avoid infection. It is for minor cuts, grazes and abrasions. The colour purple is to disguise anything reddened by blood or that is inflamed. Chickens are highly attracted to blood and will peck and peck and peck causing horrendous wounds. Purple spray is great at disguising this redness and is very useful when a chicken is moulting. Broken blood feathers can be just too tempting to plucking by other chickens.
Word of warning: Purple spray will stain anything it comes into contact with such as furniture, clothing, skin, feathers. It is virtually impossible to clean off, but wears off skin over time. It is more difficult (almost impossible) to remove it from furniture. It will fade to pink on feathers but they will stay stained till they are moulted. In light coloured chickens, try to keep the spray to the skin as pink chickens are not this years new black.
When applying always make sure your chicken is not able to flap as you put them down. Purple spray will turn you in a rather fetching smurf colour. A purple face or hands is not a great look round Sainsburys