when my buddy's little brother was in his teens/early 20's, a guaranteed way to get rid of those pesky Fobs/ spare keys, was to let him drive a particular vehicle for a while.
Their Mom's Aztek, with 2 keys and 2 factory Fobs, plus 2 aftermarket fobs for the remote start she had installed, by the time HE stopped Driving it, and mom sold it/gave it to her friend, it was down to 1 key, and Zero Fobs.
same after they bought my Neon for him. 2 Factory keys, 2 factory Fobs.
with in a year of him driving it, No fobs, 1 key. when mom moved to AK, and we cleaned out the house pre- sale, not a one of them were found. NONE.