I would try it. BTW, I don't think slime will seal a bead leak too good. On the slime website, they say it won't. They say it's only meant to seal the tread area of the tire and not the sidewalls or beads.
That Fix-A-Lat sealer might seal the bead, but I would try to avoid that if possible. It makes a mess on the inside of the tire. I would try resealing it like you mentioned. Wire brush the rim good and clean the tire bead good. If the rim still looks bad after wire brushing it, I would try to find some bead sealer to brush on the tire bead.
Also, make sure the valve stems aren't leaking while you're at it.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.