Dealing with scammers

I listed a listing on FB Sunday and I've had nothing but scammers insisting they need a history check from a specific site. I've taken to starting with the following schpeel. Would you be offended by it as a legit potential buyer?

"Yes it is [available] I'm sorry if this sounds rude, but I'd just like to get something out of the way first.

I hope you're not going to try and get me to go to a specific non government website for a history check! I jest, but I've been dealing with scammers for days! I mean no offence if you're serious. I've just gotta weed these people out."

It seems to be working like a charm. I just hope I haven't scared off any legit enquiries.