|You are right, Let me explain the procedure ...
1) Remove all clothing, and I mean ALL, and wash at least twice.
2) Shower well, this means with a good strong detergent (dry)
3) With a new razor, shave away from the body, down the legs. Then dispose of razor.
4) Maintain with an abrasive pad at least daily (Scotch Brite, white color)
I know this sounds a little extreme but the exfoliation of the skin seems reduces the amount of Urushi oil, thus reducing the amount of irritation.