Changing Prey

[Nutriaitch]

I've mentioned here before that I was underfeeding my BP before realizing his meals were too small.

He ate an adult mouse the first time I tried to feed him one with intent to switch him over to rats so he can work his way up in meal size as he gets older.

by sheer luck of timing, this happened to coincide with him shedding.
he didn't eat leading up to the shed (nothing unusual)
he shed roughly a week or so ago (don't remember exact day). looked like a good shed, mostly all in one piece with a very small piece at the tail that came off later.

over that week, I've made multiple attempts to feed him fuzzy rats.
he acted very interested. came in close smelled it, got into strike position, then casually just slithered away.

wasted 4 F/T fuzzy rats during this time.
last attempt was day before yesterday.

today, I still had a fuzzy mouse left over from previously, so figured I would see what he would do.
Wow! he attacked that thing with extreme prejudice. and wasted no time in eating it.

I know it could just be a timing coincidence and he may have eaten a rat today if I'd had one.
but I've also read that they can be stubborn when switching them between types of prey.

so my question is:
Are there any tips or tricks on best way to switch him to rats so he can get the larger prey he needs?
should I just buy more Frozen Rats (maybe try a pinkie) and try again on next feeding day?
or maybe try to find a local breeder where I can score a fresh killed rat?