Is dishwasher effluent OK for watering plants with (specifically, comfrey)?
The reason I ask, is because I am thinking of drilling some small holes in
the 2" sloping waste pipe outside my house which takes the dishwasher's
effluent to the sewer downpipe. Underneath the 2" waste pipe, is a long
planter containing my comfrey plants, which I gather prefer to live in damp
soil.

The dishwasher tablets I use are the cheapest type from Tesco. I also use
salt, in the dishwasher's salt compartment, to inhibit limescale.

Jim