Unfortunately not, some arrangements can pinch together sections of the gut as they pass through and that's a very big problem. No reticulum in toddlers. Rumination is preserved for thoughts only when they get bigger.
Specifically, swallowing ONE magnet is probably fine, since children do not tend to eat metal frequently. Swallowing multiple strong magnets brings the risk of pinching (and necrotizing) sections of the gut.
... and for that kind of rumination, we have therapists to help out.