Method Painless CTB with boric acid?

[Dazaii]

I have access to more than 200g of boric acid, and I'm wondering if theres anyway to CTB with it painlessly, since I don't have access to anything special.

 

[locked*n*loaded]

"The minimal lethal dose of ingested boron (as boric acid) was reported to be 2–3 g in infants, 5–6 g in children, and 15–20 g in adults. [...] However, a review of 784 human poisonings with boric acid (10–88 g) reported no fatalities, with 88% of cases being asymptomatic."

Boric_acid