I know you knock the electric toothbrush but please let me share what tickle techniques I find that work like a charm. First off the Crest Spinbrush electric toothbrush -rechargeable batteries-it works great, tickles like mad, especially on the soles, underneath the toes, along the heels, ankles and also another great tickle tool is the Oral B Pulsar toothbrush, don't have a rechargeable battery but pretty inexpensive, great thing you can find both these items in a nearby Walmart or grocery store, so that is a yay! The Oral B pulsar electric toothbrush is great on the spine, back of the neck, sides of the neck, arms, legs, back of knees, ok you get the point right 😉 another great tool to use is chopsticks/ or skewer sticks-you can find these in a local grocery store or Walmart or hobby store. Very inexpensive, a great tickle accessory to add to a tickle kit. use the flat end, not the pointy end-work great.
Nice large fluffy feathers and stiff feathers are awesome, you can find these at hobby stores or fluffy feathers either online or at your local adult novelty shops, or small kit of feathers and fuzzy pipecleaners and other tickle accessory tools like articificial grasses and texture tools in a local Walmart, Meijers, or hobby store, creative aisle in department store.
Most importantly fingers are always a great tickle tool, your imagination, your voice playfully taunting and teasing when doing the tickling, nice addition could be if both into light bondage when tickling-silk scarves or velcro underbed restraints, find velcro underbed restraints either in a local adult novelty shop or online adult shop, silk scarves is easy a Walmart or department store, or hobby store, not sure how strong it would be endurance wise but would work for light bondage when using it.
Make up brushes and accessories work great for playful light tickling, find those in department stores, around Christmas time-makeup kits, I mean if you are a guy you can toss out the makeup and just keep the tickle tools. Keys also work good but you got to be careful, only suggest this on the foot lightly tracing, not for intense tickling, but light tickling, works real good.
These are just a few tickle ideas let me know what you think hope this helps.