Yes, you should be safe for one day, but in that case I think you should start with 5mg oxycodone and build up to 10mg max to stay on the safe side as there will still be some clonazepam in your system. How long have you been taking the clonazepam and what's your dosage?
As for ROA, oral is best. Oxy has a 60-87% oral bioavailability while intranasal is only around 50-70%.
edit: I just read your other thread OP, it's definitely NOT safe to rapidly taper from such a high dose of clonazepam. Please take any measures possible to taper slowly and safely and save the roxis for when you have your benzo usage under control. At this point, it's really not safe to combine opioids and benzos since you're not on a stable dosing schedule with the benzos.