It really just depends on regional dialect like in Louisiana and Northern NY/Maine they pronounce it Blastwah like the French pronunciation and in the West and Midwest and Florida it's pronounced Blastus and in the Northeast and Detroit it's pronounced Blastoys like "You Guys." In Japan since they don't have an L in the alphabet they decided to just translate it literally as ใซใกใใฏใน (katakana) which is pronounced like Kamecks. I'm not sure of the Hiragana spelling but it still doesn't have an L.