The best replacement for drainage is pus.

The best alternatives to drainage are rated as following:
★★★★★  pus
★  exudate
★  irrigation
★  purulent
★  access
★  percussion
  lung congestion
  aspiration
  serosanguinous
  operation
  exudates
  discharge

Your alternative for drainage is not listed? Suggest!
Speaking about drainage, one probably shouldn't forget about ear tubes.

Other search terms related to drainage and their ratings are:
★★★★★ ear tubes
★★★★ ear infection
★★ ear tubes in toddlers
★★ congestion
★★ pavers
★★ swimmers ear
★ nasal congestion
★ infection
★ stuffy nose
★ incision
tubes in ears
sore throat
pvc pipe
sinus infection
You have in mind a companion for drainage and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of drainage in all years. Click on graph for more.
drainage
pus
exudate