I boiled some chillis in water for 15 minutes and reduced it quite a fair bit then added a jar of honey and bottled it... it is FAN-BLOODY-TASTIC poured over vanilla icecream!!
Freakin hot icecream
Best natural fertilizer is probably seaweed liquid. I use a brand called Seasol.
To break down the rabbit manure add it to a compost bin with lawn clippings, kitchen scaps etc