As a recovering heart patient, CO (carbon monoxide) in pot smoke is a major concern of mine.
Among other bad things CO does, CO gloms onto the hemoglobin in your blood with an attraction 200X greater than O2.
The redblood cell that gets it hardens and flowing through your arteries damages them.
Your body sends cholesterol to repair the damage.
Rinse, repeat, heart attack, or at least arteriosclerosis.
Though I dose 90% of the time with edibles, some days a bong hit or 6 works wonders.
Now I have no proof of this but the idea is to put maybe 10 - 50% of food grade hydrogen peroxide(3%) into the bong water as a CO trap.
The extra atom of O2 should grab the CO right outta the smoke.
I buy 35% food grade and cut it with an 11 to 1 distilled water to 35% H2O2. With the result of 3% H2O2.
Then I add that to 50 - 90% regular tap water for the bong’s res.
Full strength (35%) will kill all the cells it touches on your skin, mouth, throat or lungs 
so be sure to cut it down to 3%.
Just to be sure, if you have heart disease you’d be crazy to try this and that’s not a challenge.