I just switched my pool over to SWG. Dumped my first bag of salt in the little end and brushed it around. I used morton solar salt and it didn't dissolve as fast as I thought it would. Took about 1/2 hour to get most of it to dissolve. I had 18 more bags to go...
What I did was, place a folding table flat on the side of the pool. Please two unopened bags on the table as a counter weight. Then used a screw driver and punched holes from about 1/2 way down to the bottom of a new bag. I tied a bungee cord from the bag to the table and placed in the pool over the side of the table. Took about 30 minutes to empty the bag. you could actually see the salt cloud coming out of the bags, under the water.
Don't know if this helps anyone, but this site has helped me out a lot in the last few weeks with opening my pool and wanted to give back a little bit.