I had an ink stain, caused by another pupil stabbing me with a fountain pen when I was ten. I had a 8 W 1 MHz ultrasonic massage device – like used by physiotherapists to clear scars.
So I applied it to the skin 5 times, and the mark went. The body removes and replaces damaged cells under the influence of the ultrasound – and toitally clears the tatoo.
You don't have to cover it, you remove it! The devices cost 36 UK pounds. As I mentiuoned, they clear scars, and repair damaged joints. Not instant, but it works!