These orbs help power up abilities like Guts or Marvel Scale, along with the move Facade.
Ursaring is a good candidate for the Flame Orb because it can have the ability, Guts. Along with the ability to learn TM42: Facade.
Breloom is also good for using the Toxic Orb because of it's Poison Heal ability.
*Facade inflicts damage. Its base power doubles from 70 to 140 if the user is poisoned, paralyzed, or burned. Burn's effect of lowering attack is still applied, unless the user has Guts.
*Guts raises the Attack stat by 50% while affected by the burn, paralysis, poison, or sleep status ailments. The Attack drop from burn does not occur.
*Marvel Scale raises the Defense stat by 50% if the Pokémon with this Ability is suffering from a status ailment
I hope this helps and maybe gives you an idea on how to better use these items!