I agree that a good initial cheap start is using the peroxide.
I would not leave it in so long, though.

Perhaps 2 times a day hold head sidewise
and put about 1/2 cap in one ear.
Let it sit and bubble for about 20 minutes.
Flip to other side and repeat on other ear,
then let the fluid drain,

If you kept your hands totally
immersed in water for several days
they would get overly soggy (waterlogged).
You need to let the ears dry out between treatments.

There are many possible reasons for ear *itchings*
or congestion .
A few being, parasites (very common)
of the microbial sorts esp ...
bacterias, yeast, ear wax,
stagnant fluid trapped in ears
from showering or swimming,
lympth congestion ,
toxins storage and or elimantions
and bad drainage of body fluids
due to congestions
resulting in back up in the ears.

The oxidization treatment of peroxide,
will help in killing off bacterials, yeast,
cleansing of toxic residue from inner ear,
and breaking down wax to a degree.
Some of these things cannot survive
in a higher oxygen environment.

If the problem is due to toxic build up
and congestion,
then you need to address lympth drainage,
and body cleansing.
The ears are often the last resort of excess
toxin storage.

The answer is very low cost to deal with.
Liver and kidney flush /cleansing,
lymph draining thru rebounding, dry skin brushing,
colon cleansing (thru colonics, or even colosan ),
good exercise and food ingestion.

Avoid as best you can, getting water in ears
while showering,
If you sweat,
then do a small bit of peroxide in ears
for a few minutes afterwards,
to help bubble away the toxins that might
have been released in ears as you exercised.

If you feel it is yeast related,
then might consider drinking pau d'arco tea
or getting the herbal extract,
and add a few drops to a drink
4 times a day ,
plus you could make a warm tea,
by boiling water, add herb. remove from heat.
steep for 20 minutes, til tepid.

This is called a decoction .
Take in small doses (like a tablespoon)
thru out the day ,
and put some in each ear as well.
Pau d' arco is very effective against yeast.

There are many suggestions I could give you .
It seemed though you wanted perhaps the lowest cost
way to deal with this?
Some options include :
diluted drops of 85% carvocal oil of oregano,
Colloidal Silver , or olive leaf oil diluted.

Before and after using peroxide,
drape a towel around neck , so if you miss,
it won't roll down onto your shirt *8)
Afterwards, wipe lightly with water to get the smell off,
and rub a small bit of oil on edges of ears at night.
to avoid them drying out
thus getting dead skin flakes scales

Hope this is a help
Ami Joi Benton