Joe Glo Backflush Detergent is recommended for backflush cleaning. Instructions as printed on every container of Joe Glo Espresso Machine Cleaner:

1. Twice a day, pour a 1/2 tsp of JoeGlo Espresso Machine Cleaning detergent onto a "blind" disc insert (backflush disc) in your portafilter.
2. With the portafilter attached, backflush your machine by running the group five times in 15 second start/stop intervals.
3. Remove portafilter, discard the leftover bits and run the group to rinse away the crud.
4. Use a quality group head brush like the Pallo Coffeetool to get rid of any residual oils or loose grinds.
5. Reattach portafilter and backflush five more times in 5 second start/stop intervals, this time without detergent.
6. Once again, remove portafilter and run the group to rinse clean.
7. Replace the 'blind' insert with a normal filter insert then pull and discard a couple of shots to "re-season" your machine.