I don't keep bloods- & have no experience with them (others who do will likely comment soon), but I'll just offer this thought: both digestion and shedding require extra hydration (water) from a snake's body to accomplish, so it's possible that he's feeling the need to soak because he's maybe going into (or already in) his next shed cycle. Snakes appear to "know" before we can see any evidence of shedding (such as their clouding up), & often refuse food at that time, but if they accept food, what you're seeing might be the result. How long have you had him? When was his last shed? I would trust your blood to know what he's doing & let him keep doing it.