Meanwhile, prosecutors said Friday they expect to decide next week on what charges to file in connection with the episode, which occurred at the Dickey's restaurant at 689 W. South Jordan Parkway.
On Aug. 10, Harding and her husband were lunching at Dickey's when she took one sip of her sweet iced tea and began gagging and coughing.
The 67-year-old woman suffered burns to her mouth and esophagus. Doctors at University Hospital had to insert a breathing tube. It was six days before she could speak again.
She left the hospital Aug. 23.
Employees at Dickey's quickly discovered that an industrial degreasing solution apparently mistaken for sugar had been mixed into the tea, according to police. The solution was 67 percent sodium hydroxide, which is the active ingredient in drain cleaner, commonly known as lye.
Harding said Friday at a news conference streamed live by KUTV2 that all chemicals should contain a dye or colored crystals to differentiate them from food items.
And cleaning agents should be clearly labeled and not be stored anywhere near the kitchen, she added.
"I'm hoping to see and hear some good come of this ... see [restaurants] become proactive to keep this from happening to anyone else," she said.
There was no hint of it Friday in Harding's clear, calm voice, but the lye burned her mouth and esophagus and caused her airway to swell shut.
Doctors initially feared she might die.
When her breathing tube was removed after several days at the hospital, Harding said she could not swallow her own saliva, which had to be suctioned away. And there was a tube to suck everything out of her stomach.
"I could not brush my teeth for seven days," she said.
Harding was sent home on her 46th wedding anniversary. She said she watched a movie and danced with her husband.
But she could still face complications.
Doctors will probe her esophagus next week looking for scar tissue that might impair her ability to swallow, she said.
"I'm hoping and praying that won't happen," she said, adding: "God hasn't failed me yet. He's not going to fail me in the future."
Jim Harding, interim pastor at the Crossroads Church in Sandy, said the episode has strengthened his faith.
"A genuine faith makes a difference, and our God is real," he said.
Salt Lake County District Attorney Sim Gill said Friday the case was presenting his screening team with some complications. Still, he predicted that he will know by "the middle to end of next week" the nature of the case involving Dickey's.
"We met [Thursday] with South Jordan police [detectives] for two hours and reviewed the investigation. We haven't reached any final conclusions yet," Gill said. "
Paxton Guymon, the Harding's attorney, has said he is investigating claims that restaurant employees discovered the cleaning chemical had been mixed with the sugar weeks before it ended up in Jan Harding's tea, but they did not throw it out.
Witnesses reported that an employee told a manager that the sugar looked unusual, so the manager dipped a finger into the container and tasted the white substance, police have said. The manager sought hospital treatment for the resultant blisters and bleeding on her tongue, Guymon has said.
"We were told this bucket was moved," Guymon has said, "but we don't know where it was moved or how it was stored or why it was available Aug. 10."