I curse that lame, way-too-short 1960s-era dipstick design on my FJ62 - I may add your silicone sleeve trick.
Maybe there's a low-rider 'bling' LED thing I can put around the dipstick tube - it's no dumber than light-up wiper nozzles on your hood, right?
It occurs to me, you could put some, um, 1/2"? tubing over the top of the 3/8" and leave it long enough to go to the bottom of the finger ring on the dipstick. . . should be big enough for the stopper on the dipstick to go down and it would guide the dipstick down the pipe. . . maybe.