Plugging becomes routine and easy once you do it a few times, and thats for any drug honestly. As long as it's water soluble of course.
I recommend going to your local target or walmart and asking for a few oral syringes, the ones without needles obviously. I usually plug using the 1ml syringe because it's the smallest and usually works with most material. If you happen to need a little bit more water however a 5ml syringe works good too.
I have no experience plugging any opioids so I can't comment there... I would assume start with a lower dose than your usual oral dose but I can't remember if bio-availability is really any better with opiates when plugging.