I don't know about a 'great experence' -but no doubt about it: Muck Munchers work.
1. My septic tank lasts at least four years between emptyings - a saving of about £300.
2. No dubious smells - even on hot summer days.
3. Congratulating me on the condition of the tank, an experienced operative said "You use Muck Munchers, don't you?"
4. All this for about three quid a month!