I use tons of biosolids - probably quite literally! I frequently use organic fert similar to milorganite, but out of New York and the mulch that I use almost exclusively if a blend of aged bark and compost the is made primarily from biosolids. It is sold through a company called New England Organics and I can tell you, the stuff is awesome! It has a nice fine texture that spreads nicely and it adds a boost of nutrients to the garden beds. I will admit, when I dig into the pile with the tractor, that burst of steam has a distinctive scent, although not offensive, but once its spread in the beds, you can't smell it.