During his first privilege speech, the neophyte senator answered Senate Majority Leader Vicente Sotto's query by initially stating that he just wanted to focus on bringing back the death penalty.
But later on, Pacquiao answered directly and revealed which method he preferred for practical reasons, the Inquirer reported.
"Para po sa akin sa ngayon, nananaig ngayon ang hanging or firing squad," he said, adding in jest, "Sisipain lang po yung upuan."
Senator Francis Pangilinan called him out for the joke, saying it was distasteful to talk lightly about things involving the life of others.
Meanwhile, GMA News Online noted that Pacquiao mentioned in his speech that he has already filed Senate Bill No. 185, which seeks to reimpose the death penalty.
The bill states that it is "an act to impose the Death Penalty and increased penalties on certain heinous crimes involving dangerous drugs, amending for that purpose other special penal laws, and for other purposes."
"Wala tayong dapat ikatakot sa death penalty dahil ito ay para lamang sa mga taong walang habas gumawa ng karumal-dumal na krimen," Pacquiao said before quoting some verses from the Bible.
Last week, President Rodrigo Duterte met with Pacquiao in a bid to seek the boxer-turned-politician's backing in pushing for the revival of the death penalty through the Senate.
The reimposition of the death penalty is among Duterte's legislative priorities as part of his war against illegal drugs.