The IT worker is accused of poisoning the couple with the powerful painkiller fentanyl and rewriting their will to make him a director of their shower mat firm Cazsplash.
Their daughter Ellie, who found her parents dead at their home in West Mersea last Easter Sunday , watched from the public gallery as the defendant gave his evidence on Tuesday from a wheelchair.
He was cross-examined by Ms Ayling about the emails sent by a fake doctor, who prosecutors say was Mr D’Wit.
Ms Ayling said they told Mr and Mrs Baxter to drink boiling water, lemon and aspirin tablets.
“You mixed that up for them, adding in aspirin that would have no effect on the liver, and you threw in a fentanyl patch for good measure,” she said.
The defendant replied: “No.”
Mr D’Wit also denied he gave Mrs Baxter a tack, found in her system in February 2022, inside a tablet.
