To do these 'techniques' safely; I use a speed-adjustable electric scroll saw, an empty silicone glass sealer plastic tube that has a few small holes punched through the closed end to allow the air to escape, and a double-ended dildo.
For jerking off: I connect the empty silicone tube to my scroll saw. (I invented a special 'connection between the empty silicone tube and my scroll saw that keeps the saw well away from my body and sensitive parts for safety). The empty silicone tube is just the right size for my hard cock. Then I stick my hard-on into the tube, turn on the saw (starting with the slowest speed)and let it pump away on my cock until I cum inside the tube, while I play with my right nipple and pull on my balls, and adjust the speed of the saw to fit my needs....at the same time, with my two free hands, I can finger my asshole, play with my nipples or read porn.
For anal play: while I slowly jerk-off, I put one end of the double ended dildo into the empty silicone tube (it fits snugly). Then I stick the other end of the well lubricated dildo up my ass, turn on the scroll saw and let it fuck me, while I jerk-off...the hands-free stimulation from the rapid motion of the scroll saw fukcing my asshole is simply awesome. I see a lot of guys, straight or gay, love asshole stimulation, like me. I suggest doing this in bed,(put a towel over your sheets) or on a carpeted floor, and being very careful of the electrical power cord, or shocking yourself when you cum...
For lube on my cock (and on my nipples and my balls) I love to use baby oil. For my butt, I use water-based VS hair treatment. It has a parafin wax additive that makes getting fucked very easy and pleasurable.
Another way I sometimes jerk off, is I'll put my balls in my penis pump and pump until my balls and scrotum fill about 1/2 the tube. The extreme tension on my balls gives me an awesome orgasm, while I jerk slowly with my right hand, and play with my right nipple (it seems to be hot-wired to my cock) with my left hand. I've been jerking off 2-3 times a day since I was 12 years old...and I'll keep doing it till the day I die. Think I'll do it now.