Well, you may not like this answer...

GYA PHRF is an outlier on the issue of dry-sailing. ORR-Ez is just like ORR, ORC, IRC and every other major PHRF area in the country, in that there is no rating adjustment for dry-sailing. All these rating systems assume that every boat is "race ready" which includes a clean, fair bottom. If you choose to sail with a hairy hull or ratty paint, that's on you!

The forum thread linked below is classic Sailing Anarchy with a bit of trollery, but as a whole, it's a fairly balanced take. An interesting read that covers the pros and cons of both.

Kett