@ Feidhlim Harty :Grey water fed hugelkultur...

Not having seen this suggested, I search greywater forum for it, and found next to nothing I would love to gear you opinion of it.
seems like a natural, yet I can see wanting more small bits of carbon than a hugel normally has.
If seed with a hand sink->urinal like I mentioned in another thread, It could do a lot to alleviate any nitrogen suck that the wood might bring.

Old threat but...

Logs at the bottom of a grey water mulch pit is interesting. In his book, Art Ludwig mentions that you want to use material that won't break down so easily. I wonder if that would work.

I guess you are not talking about a mulch pit though, just a regular hugel with a pipe sticking in it.

What did you end up doing?