Why would you want to get addicted to suboxone to get rid of oxycodone cravings? Sounds stupid to get addicted to an even harder substance simply for the fact that you have no ways to cope with a craving. Get some therapy, goto rehab, or live with it.
No one ever has to touch another drug for the rest of their life, discounting ones that you need medically. If you take a drug that causes withdrawal if you don't take it, and you're not perscribed, then it's time to detox.
If you take a drug to satisfy an urge, then you are making a decision to. If you can't handle the urges, you should get psychological help or rehabilitation, because you need to find other ways to deal with cravings besides taking a drug.
Don't blame the cravings, it's your lack of willpower that makes you take the drug. Nothing else. You can learn ways to deal with it and improve your willpower, so it is entirely your fault if you take a drug when resources are available to help you stop.
If resources aren't available, then do something about it. Again, everything you do in this life, or don't do, is ALL YOUR DOING. Don't blame a substance, a subconscious impulse, or lack of motivation. All these can be worked through. If you don't think so, you most likely are ignorant and have never given professional help a real shot.
Change your life around. Get a grip.