It would be nice if people stopped writing this in their descriptions. Giveaway creators are not allowed to create their own rules or stipulations in the giveaway descriptions. Anyone that can see this giveaway can enter and does not have to agree to anything outside of the site rules. The option to delete the giveaway if the key does not work will always be up to the giveaway winner no matter what is written in the description.

Here is a comment from a mod confirming this. It is mentioned in the 2nd paragraph of the comment.

I don't have a problem with deleting the giveaway and I think most people will agree to delete the giveaway, but if they do not, having a not received on your account is not a big deal. We never used to delete every giveaway that had a problem in the past and it wasn't a big deal.

If you think there is a chance the key will not work, there are a couple groups made specifically for this where the group rules state that the giveaway creator must agree to delete the giveaway or they will be kicked from the group. That is allowed because it is a rule for the group and only people that are in the group can enter the giveaway.

Delete giveaway group
Lootboy SG group

Thank you very much, the key is working :)