just dont leave it in. if you put it in the oil, change the oil, if you put it in your gas tank, burn all the gas back up and fill it up.
seafoam (kerosene) eats rubber, so you dont wanna leave it in for long.
I seafoamed my m52b28, i was happy with the results.
Hot: 2001 Estoril M Roadster
ZCP 19's, ZHP knob, JL 8W3
Cold: 2002 TiAg M3 6mt
ZCP 19's supersports, ZHP knob, UUC short shift GROM, OEM 18's w310's,
http://absolutehid.ca hid kit