The best replacement for diffuser is softbox.

The best alternatives to diffuser are rated as following:
★★★★★  softbox
★★★★  register
★★★  nebulizer
★★★  bounce card
★★  humidifier
★★  bounce
★★  candle
★  reflector
★  hair dryer
★  bouncer
★  absorber
★  downstem
★  reactor
★  perc
★  air dry
★  bounce flash
★  grille
★  umbrella
  burning essential oils
  nozzle
  percolator
  spray
  blow dryer
  condenser enlarger
  diffuser
  volute
  concentrator
  no diffuser
  air stone

Your alternative for diffuser is not listed? Suggest!
Speaking about diffuser, one probably shouldn't forget about essential oils.

Other search terms related to diffuser and their ratings are:
★★★★★ essential oils
★★★★★ feliway
★★★ hair dryer
★★★ feliway for cats
★★ blow dryer
★ d.a.p. for dogs
★ flash
You have in mind a companion for diffuser and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of diffuser in all years. Click on graph for more.
diffuser
softbox
register