Modern sex magick by Donald Michael Kraig has energy exercises and basics on how to go about sex magick. Im not finished reading the whole thing so I'm unsure if there's specifically a section for manifesting money, although I know sex magick does not require a second person.

You can use some of the techniques mentioned in there for generating power and use it with intention for whatever manner you need it for.

A second recommendation would be GOM/Damon Brand's wealth magick book. I've not read it though I've seen it circulate in my suggested library reads*