Healing a flaw is a great opportunity for character growth and adventure.
Take the Tender Skin flaw. Normally magic should be able to alleviate the rashes and what not, but for some reason, magic does not have the same affect in this case. The why is were the adventure may lay. A long ago magic, blessing or curse suffered or gained or lost by an ancestor or even being born under a certain moon, star, at a specific time or place or comination of the three; exposure to something, an unfriendly witch...whew, thats a run-on sentence from hell...
...anyway, you get my point. Use the desire to remove the flaw as an avenue to a bigger adventure, open some doors and let the madness begin.
I bet you get five to twelve sessions out of it, easy.