Need Advice On Deletion Request on Credit Repor. Thanks!

[NailesP]

I am making a final payment tomorrow to a collection agency, Arrow Financial to be exact. I have read some not so great things about them, but only after I had payed quite a few payments into a settlement agreement they offered me. I want to make sure they close this account out and if possible I would like it to be deleted. I would think they will go for the deletion request since they obviously know I am going to pay it off due to my fulfilling of every other payment. Should I use the Validation Settlement Offer with Deletion Requirement letter? Also, should I get it notorized? I realize this is about a debt, but the deletion would effect my credit, so I'm posting it in this forum. Any help will be greatly appreciated!