Mr Horan did not notice oil all over his daughter until the family returned home - as he and his daughter travelled in separate cars - and saw oil spots all over his new furniture.
"I thought how did that get there, then I took one look at her and she was absolutely covered in oil.
"It's disgusting, just unbelievable," he said.
"She was playing with other children [in the sand hole] and if these poor kids put their heads under the water [in the hole], then this oil would get into their eyes and in their ears. I think it's terrible."
He immediately placed his daughter into the shower and used olive oil and a flannel and removed the oil globules from her body and hair. The olive oil offered relief and washed the oil spots away "very easily", he said.
Mr Horan wanted to warn parents of the dangers of oil on the beaches.
He was angry the oil had not been removed from the Western Bay coastline.
"I consider myself to be pretty aware but we can't have young children bathing in toxic waste," he said.
"As a parent I want to warn other parents but as an MP I want answers, because it's not good enough for people in Tauranga to bathe in a toxic mess."
The olive oil easily removed the oil off Leilani's body and she was left without a scratch or hint of irritation. Her pink togs were put into the washing machine but the oil did not budge. He did, however, manage to get the oil off his couch.
Papamoa Surf Club patrol captain Shaun Smith said last weekend was "huge" and estimated there were about 800 people on the beach.
He had heard of a few cases of people getting oil on themselves "but only when they've been digging in the sand".
Mr Smith said there had been no reports of oil in the water.
"I would say the beach has been cleaner than normal.
"Normally I go down to the flags and see a few spots [of oil] but I couldn't see anything today."
Warning signs remain in place along the Western Bay of Plenty coastline, which stated the beach was "not the same as it was before the Rena grounded".
On the sign it said small amounts of oil would continue to resurface in the water and on the beach, which Maritime New Zealand spokeswoman Sophie Hazelhurst said would continue for some time.
"Maritime New Zealand is continuing to seek and receive reports of oil in the sand and water that members of the public have come across.
"This is expected as, although there has been a huge clean-up effort, residual oil will continue to surface in the environment for some time.
"There is oil buried in the sand, on some of the rocks and, in some cases, submerged in the water.
"This will continue to resurface with tidal movement and will be most evident after periods of rough or stormy weather."
Toi Te Ora Medical Officer of Health for the Bay of Plenty and Lakes District, Dr Phil Shoemack, said a significant proportion of oil had been removed from the Rena but "unfortunately it's not possible to get every last drop out" and oil would continue to be found on beaches across the Bay of Plenty for a while to come.
"The oil is of much less concern now than it was when it first washed ashore and this oil is unlikely to cause any health problems. But it is still our advice to avoid getting oil on yourself and, should you get any on, wipe it off with soapy water as soon as possible," Dr Shoemack said.
Should any health symptoms appear, seek the advice of a health professional.
Ms Hazelhurst said Maritime New Zealand would continue to assess, clean and re-clean the beaches along the Western Bay coastline. She said while Maritime New Zealand did have trained oil spill responders assessing beaches every day, they could not be everywhere and the public information they continued to receive was invaluable. She said every report was followed up.
Maritime New Zealand urged those who come across oil on beaches - whether buried in the sand, in the water or on rocks - to contact 0800 OIL SPILL (0800 645 774) and give the best description of the oil they can, including its location and the amount seen.
If you are concerned about possible health risks as a direct result of the oil, visit www.toiteorapublichealth.govt.nz for more information.
