Blocked drains

[stanbesida]

Could anybody advise me how to remove grease from the drain?
I have gone from one end of the pipe and have used a spider and went 10 rods into the pipe, but it hasn't cleared it, I have also tried a Karcher drain cleaner but that didn't work either. I rodded from the drain end and used 10 rods from that end as well but the rods came out of that end with a white grease on them, I have also used the Karcher drain cleaner from that end, but I assume that there must be a blockage of grease somewhere in the middle of the pipe. I have filled the sink with hot water and put soap powder in it and I also put soda in the hot water as well, but none of this has cleared the grease. Could anybody suggest a way of clearing the blockage, the water is running slowly but I assume that whoever lived here before me must have emptied grease down the drain and it has become blocked over a period of time