i tried to go with the link you gave it got me nowhere
https://docs.google.com/document/d/10VsCUMPg2tcTtwy8uqJryrAdQdetlUj29pEh70kLFjE/... I've uploaded the sex guide to Google Docs -- PasteBin rejected it for containing adult material.
for Sandslash specifically, you just don't need to worry about the balls -- just make sure to rub her pecs/breast and vagina like the guide says.
The guide mostly applies to both genders, for characters where it talks about the penis -- you can use the same strategies for their vagina if they are female.