Kingsley said Lomu had made himself available to play in New Zealand's national provincial championship in August, hoping to persuade the national selectors to include him for the World Cup in October.
"This is the fourth week into his dialysis and talking to him on Friday he said he hasn't felt so good in the last nine years," Kingsley-Jones told Channel Seven's Rugby Zone.
"It's obviously doing him the world of good. He goes to dialysis three days a week and he's on the machine for four hours.
"He's feeling good and he's indicated through me to Wellington Rugby that he'll be available for the National Provincial Championships"
Kingsley-Jones said a transplant was off the agenda at the moment though he'd been taken aback with the number offers from potential donors.
"If I had a fridge - I'd have a fridge full of kidneys," he said.
"It's been overwhelming the offers from people but Jonah doesn't want to be treated any different to anybody else. But at this moment in time a kidney transplant is not what we are talking about.
"It's going to be there down the line but not at the moment - he's very happy on the dialysis."
Lomu has been troubled by the kidney complaint for several years and was forced to withdraw from rugby early in the 2003 Super 12 competition to step up his treatment. Kingsley Jones said if Lomu's training was any indication a successful comeback was on the cards. He'd been working with a personal trainer and was to train with New Zealand sevens great Eric Rush this week.
"He's training every day and training with aggression," he said.