F/T mouse fell apart

[Bogertophis]

...He comes right out when he sees the f/t, smells it, and looks repulsed. He turns around and refuses it.

Because it's spoiled! Be glad he refused it...If you thaw correctly, it shouldn't spoil as yours did. The way you did it would have gagged a maggot.

I thaw in cold water first...(-not laying in 'fridge...the fastest temperature change happens in water & a faster thaw means no spoilage). How long the
cold water takes depends on how many you're thawing & how big they are. An adult mouse will take about 30 minutes, a rat will take a lot longer.
(You can change the cold water if it gets too "icy", but don't use hot or warm water until they are thawed.)

Once it's thawed completely (feel thickest part of rodent to be sure the inside is thawed), then briefly immerse in warm (NOT HOT) water to warm it up.

Use a blow-dryer to make it extra warm if feeding a "fussy" snake (like most BPs). I just blot the water off on a paper towel & feed immediately, as I
don't have any BPs currently.