We used child locks that fasten to the inside of the drawer and the hook is fasten to the frame opening. I think they are 6 to 8 in a pack for under $5.00 when we bought them. After we installed them we never had any doors that would open up on our old Cougar. Have not had the need for them on our Cedar Creek as of yet.
2016 34RL CC; 2008 Ram Mega Cab 2500HD, 6.7L, 68RFE 6 speed, 4X4, Smarty S67