Don’t do it bro. Most likely doesn’t get you higher and most likely increases risk to smoke damage/cancer in lungs.

https://pubmed.ncbi.nlm.nih.gov/2554344/

https://pubmed.ncbi.nlm.nih.gov/2027922/

https://www.gov.mb.ca/health/cannabis/myths.html

Breathhold duration and response to marijuana smoke - PubMed

Marijuana smokers are frequently observed to hold the smoke in their lungs for prolonged periods (10-15 sec) apparently in the belief that prolonged breathholding intensifies the effects of the drug. The actual influence of breathhold duration on response to marijuana smoke has not been studied. The …

PubMed
Interesting, tks!