I don't play scratch offs , but I will try and answer your questions
If someone in a store ( or anywhere ) , has told you something ( thus the questions you asked in this thread and the other one ) that you feel is not true , find a ticket checking machine on the counter in a retail store in the state anywhere that sells lottery tickets , hold the bar code on the ticket under there , and check it yourself ( and don't rely on people that you might not know to check it ( or to tell you what it is worth )
It doesn't hurt to scratch off the prize amount with your numbers ( as Ridge has already mentioned )
And also you can cash a winning ticket in at any retailer ( in the state ) that will cash it , as ThatScaryChick mentioned in your other thread
Per your questions , be advised that they scan the bar code on the ticket to read it , so it doesn't matter how you have scratched it off on the front , as long as the Bar Code is intact , and can be scanned
If you still have any doubts , keep possession of your ticket , and get someone you know and trust to help you , or contact the State Lottery with any questions that you may have ( they usually have a toll free number you can call )
There are some scratch off ticket games out there these days worth a lot with the top prize
So be careful with your ticket until you know for sure
Contact your State Lottery if you have any doubts at all