If you want to make it less messy:
1) FIll a 5 gallon bucket, or other your preference, with 5" of diesel.
2) You should already have the damper bolts removed but i f you don't remove them.
3) Put the fork nut with its rubber washer back in the top of the fork tube.
4) Place the fork leg in the bucket.
5) Pump the tube up and down to draw the diesel in and out of the fork leg.
6) Draw diesel into the fork leg and quickly remove it from the bucket turning the assembly up side down so the diesel can get into the tube and clean everything up in that area.
7) Flush everything back out of the assembly and set aside.
Now when you pull evrything apart it is already clean and ready to be blown off and reassembled.
This relieves you of looking down into the leg and trying to figure out how your going to get all that crap out of the bottom of the leg...
A much cheaper alternative to the fork seal tool is to use a pvc coupling, that fits over the tube, an ABS reducer to go form the coupling to a 2" PVC pipe about 3' long. Slide the assembly over the tube and slide the assembly up and down to drive the seal in nice and clean.