Those things were outlawed and gotten rid of decades ago.
If you want to do that kind of thing, find a nice secluded beach that has a tidal range to suit your draught and lay her over on one side and scrape and paint.
Then on the next tide, lay her over on the other side and scrape and paint.
If during the process you get overflown by a white twin engine aircraft with red stripes, you are BUSTED and your life is over. Boat confiscated and a big fine.
There are no cheap alternative ways of doing things in the yachting world these days.
The authorities do not like Gypsies and prosecute Pirates.