DR JOHN G, DR JANE, & DR JEANNE.....
Yes you can just dab the tea tree oil directly on the skin tag. You can cover it with a small band aid if you like to protect your clothing.
Use 100% tea tree oil.....sometimes there are a few additives that won't hurt, but get as close as you can. It usually takes about six weeks of daily use.....BUT no pain!
I found the roll on at - of all places - Dollar Tree - in the health and beauty aisle with the shower gels, etc, etc, etc.....about the size of a lipstick.