Alternatively, you could look for a banned Senior member account. It would be totally worthless, you probably wouldn't receive negative trust for farming/spamming/scamming/etc, but it would allow you to test out your signatures. I don't think that would be considered ban evasion (since you weren't the person who received the ban), but it might be worthwhile to double check that with a staff member if you're interested in proceeding with that idea.