Maybe you'd like to do a re-take, and record a Racket again after you published it. Maybe the time for an idea has come and gone, and you'd rather pull something old after publishing it.
Either way, you can delete any Racket from your Racket My Posts page. There, find the Racket you want to remove, and click the red Delete button beside it. Confirm, then your Racket will be gone for good.
You could also first click Download and save an mp3 of your Racket first, just in case you want it later, and then delete the Racket from your public profile.
Do note: If you recorded a Racket with guests, then delete the Racket, it will be deleted from your profile and your guests' profile. Or, if you joined someone else's studio to record a Racket as a guest, the person who started the Racket recording as a host is the only one who can delete the Racket.