The best replacement for stimulation is simulation.

The best alternatives to stimulation are rated as following:
★★★★★  simulation
★★★★  ultrasound
★★★  nerve stimulation
★★★  tens
★★  parasympathetic
★★  nmes
★★  e-stim
★★  ect
★★  inhibition
★  direct muscle stimulation
★  muscle stimulation
  neurofeedback
  deprivation
  physical stimulation
  sensory integration

Your alternative for stimulation is not listed? Suggest!
Speaking about stimulation, one probably shouldn't forget about acupuncture.

Other search terms related to stimulation and their ratings are:
★★★★★ acupuncture
★★★ eeg
★ tens
★ extinction
You have in mind a companion for stimulation and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of stimulation in all years. Click on graph for more.
stimulation
simulation
ultrasound