...except that smeargle's ... well, every stat except speed is abysmal. if he's looking for a long-term solution, his best bet is breloom. shroomish (not breloom, so don't evolve) learns spore at 54 and false swipe as an egg move.
if leveling a shroomish to 54 is too time-consuming, and he has access to fr/lg, then parasect learns it at 27. swipe is also an egg move for it. breloom > parasect for its better attack stat, and the ability to outrun snorlax.
false swipe can be passed on to it by sceptile (learns at 59, i believe), or through a chain from zangoose or smeargle -> seedot or mawile -> shroomish or paras
or, scyther or ninjask -> paras ( -> shroomish)
(XD owners only) or, for the highest attack possible on a false-swiper, marowak with thick club. it learns false swipe, swords dance, and sing when you purify it.
other than the box swablu, those are all the pokes in the game that learn false swipe and a sleep move: marowak, parasect, breloom, smeargle
WARNING: if the only game you have is sapphire, you're more or less out of luck. the only way you can get anything with spore/sing and false swipe is by using a smeargle, a paras, a zangoose, a box swablu, or a XD marowak, even though shroomish is in sapphire, because there's nothing to pass it to him.
EDIT: evan, what would he need ML for? lati@s, maybe, or catching abras. but those are narrow enough that it's really not worth it. the only one who has decent speed, of the options, is smeargle, and he dies to a single latias psychic most of the time anyway. the rest of them wouldn't be fast enough to Look it before it runs. now, if ML worked in safari zone, i'd already have this smeargle.