Hello! My 4 yr 8mo old 37-38lb DS has been BEGGING me to let him switch to the seatbelt HBB mode with his EM. I keep telling him no, he's not big enough, even though I think that he is mature enough to ride in it properly. Well, last night he threw up ALL OVER his seat, through the straps, buckles and everything. I had to completely pull it apart to clean it, but the straps still smell terrible. My question is, should I just say forget it and let him use the seatbelt, or should I keep trying to get the smell out of the straps and put it back together? Any tips on getting the stench out if you think I should reassemble it?? Thanks!!