He accused Mr Odinga and his Azimio allies of “looking the other way as the cost of living hits the roof”.
The DP promised to lower the cost of drugs, food and other essential commodities if he succeeds President Kenyatta next month.
He said the cost of a bag of fertiliser would reduce “from the current Sh7,000 to Sh2,500” if he becomes president.
Dr Ruto also promoted his bottom-up economic model, saying it would build small-scale businesses through affordable and accessible credit.
The Kenya Kwanza chief addressed roadside rallies in Mwingi and Mutomo townships in Kitui County as well as Machakos and Mlolongo in Machakos County.
The Ukambani tour came a day after Mr Odinga and his running mate Martha Karua were in the region which voted overwhelmingly for the Azimio presidential candidate in 2013 and 2017.
The DP was accompanied by former Nairobi governor Mike Sonko, Machakos Governor Alfred Mutua and former Nairobi deputy governor Jonathan Mueke, the United Democratic Alliance candidate in the Kitui governor contest.
Characterising Mr Sonko as a hero, Dr Ruto said the former Nairobi governor is a victim of the March 2018 truce between Mr Odinga and President Uhuru Kenyatta.
“Yet they did not join us when we supported Sonko’s Nairobi governor bid in 2013. We shall accommodate (Wiper Party leader) Kalonzo Musyoka in the government we form together with Mr Sonko,” he said in Kitui town.
“Odinga does not mean well for the region. I have told Kalonzo that he is being duped. The Constitution has no provision for a chief minister post,” Mr Sonko said.
He also accused Ms Karua and Chief Justice Martha Koome of engineering the tribulations he faced with the Independent Electoral and Boundaries Commission and the courts in his failed attempt to join the Mombasa governor race.
Dr Mutua said Dr Ruto would form the next government.
“Let us vote for Ruto to redeem Kalonzo and the entire region,” he added.
Dr Ruto criticised Mr Odinga for skipping the presidential debate last week.
Though Mr Odinga said he had skipped the debate because he had a problem with Dr Ruto whom he said has integrity issues, the Kenya Kwanza Alliance presidential candidate said his Azimio rival chickened out.
“I wanted to challenge him to explain when his allies involved in the Kenya Medical Supplies Authority scandal would refund the stolen money and be charged. I was waiting for him to explain state capture because his sponsors have captured the country’s economy,” he said.
“I wanted to put him to task on his role in stalling the Big Four Agenda, leading to the high cost of living. Now that he ran away from Ruto, will he face al-Shabaab?”
The DP said Mr Odinga cannot be the commander-in-chief of the armed forces.
“Will he face cartels and those who have raided public coffers?” he asked.
“Even if he has a problem with Ruto, he should have honoured the more than 30 million Kenyans who were waiting for the debate.”
Otherwise he is contemptuous and we shall deal with him at the ballot”.