When it was time, the former kitchen hand would head to the men's toilet.
Inside one of the cubicles, he waited anxiously while his colleague poured the contents of the crystal-like substance onto a "sampan" made of aluminium foil. After lighting up the crystals, he inhaled the white smoke using a straw.
"That's how it was almost every other day before I was caught," said Mr Muhammad, a 22-year-old part-time student.
"After one session of 'sejuk' (slang for Ice or methamphetamine in Malay), I suddenly had this abundance of energy to last the work day."
Mr Muhammad, however, is no longer taking drugs. He has been clean since last year, after completing his sentence at the Drug Rehabilitation Centre (DRC).
But the ex-addict felt so compelled to tell his tale that he turned up at The New Paper office last month with his tutor.
His biggest concern? That the drug is still so available to him that he can easily fall back into a dizzying spell of self-destruction.
Said Mr Muhammad: "If I want to score some Ice right now, I just need to make one phone call. It's as easy as buying a movie ticket."
While his stint in the DRC in 2012 was "quite sobering", he said that temptation still exists. His last job was at a catering company, which he said is a "hive" of drug activity.
Said Mr Muhammad, who was 20 when he was taught to smoke Ice by a 17-year-old: "I realised that I didn't want to be a part of that lifestyle any more, so I resigned."
He experimented with Ice because he could not cope with school and part-time work simultaneously.
After a full day in school, he had barely enough energy to perform his work duties. Yet, he needed the cash badly as he did not receive any allowance from his parents.
"The first few times, my colleagues said I could smoke for free," said Mr Muhammad.
"Later, because I wanted more, I found myself spending what I earned at work to buy Ice."