Thetford Cassette & Bio capsules

Hi, New to 'motorhoming' for a couple of months now, and finding this forum more than helpful.  However, I've been reading through a thread extolling the virtues of using 'Bio washing capsules' as opposed to the recommended chemicals.  I didn't see many, if any, comments relating to Thetford Cassettes, so before I try this out.......  do they work in the Thetfords?  If not, in an effort to save a little money and produce a sweeter smell, what can be recommended please? Thanks.