I had a blocked drain from kitchen to septic tank, OH couldn't clear it with rods etc so we sent for a man (I have an insurance for such things). He blasted it with some power jet thing and and cleared it but pulled back some hard stuff that had been blocking it. He said it was fat or grease build up and to get some stuff which would digest the grease and clear the drain/ septic tank.
Although he seemed fairly knowledgeable on septic tanks, he didn't know the name of this stuff ( came from the city nearby) . So does anyone know what this stuff is called? Also, has anyone used it, does it work and is it safe for my old, type septic brick built tank (not Karglaseter or whatever they are called) .
All helpful replies appreciated as usual. Thanks in advance.