You can if you know the variable, but I wouldn't recommend it, I don't like messing with the cheat mod too much.I've going into Janice room for over 40 days now, skipping when john's home.
Pretty sure it's not that rare an event.
Other question can I give myself the male latex suit with the Cheat mod?
but you should be able to buy it from the fetish store.
one thing you can do, is download my "Completes 0.18" save (link in the signature) and pickup from 0.19, you should still be able to step 297.