Just give her time, and Caitlin will do it for free.
This is what she looked like yesterday as we were leaving the park.
It's what she looks like pretty much every day--until she gets home--at which point it all falls off her as if she were made of Teflon.
Yesterday I forgot to put the baby gate up to keep her out of our bedroom. I found her sleeping on Rob's pillow about an hour later. There was so much sand in the bed, I couldn't see the sheet, although I could just about make out the pattern on the coverlet (the parts of the coverlet that Caitlin hasn't chewed holes in, that is.)
Judging by the amount of sand in our bed, I estimate that it would take Caitlin between 6 months and a year to transport the entire dog park into our bedroom.
Eight San Diego beaches are scheduled for beach replenishment starting next weekend. If there's any sand left over, maybe it could be used to replenish the dog park after Caitlin has denuded it.