Guys I used rocks to get all the bad rust out of my tank... they did a good job.. Well I got all the rocks that i thought was in there.. Well after I flushed clean and put fresh gas in it... I notice abut 9 rocks stuck in the side cracks where the tank slims down... I could not get them to budge with a long flat head screw driver... will it be ok to leave them in there? I hate to try to tear the tank up getting them out.