The ex-boyfriend of reality TV star Ferne McCann has told a court texts he sent about "acid" referred to hair-thickening shampoo.
Arthur Collins, 25, who is accused of an acid attack in a crowded nightclub, said he kept the shampoo in his car to hide his hair loss from his girlfriend.
Wood Green Crown Court heard Mr Collins has undergone two hair transplants.
He admits throwing a substance in the Mangle E8 nightclub in Dalston, east London, but denies knowing it was acid.
More than a dozen people were injured in the early hours of 17 April after a row broke out between Mr Collins and another group of men.
A week before the attack, Mr Collins sent a text to his sister saying: "Tell mum to mind that little hand wash in my car acid".
He told jurors the message referred to the shampoo, which contained amino acid and coconut oil, and he was worried about his nieces finding and "biting it".
Mr Collins said he kept it in his car to hide it from Ms McCann as "she would have asked me why I was using a shampoo like that".
George Carter-Stephenson QC, defending Mr Collins, asked: "How good are you at misleading her? Can she tell when you are lying to her?"
"Yes she can," he replied.
Jurors were also shown other products he had tried including Regain and Professional-C Serum.
Mr Collins' sister Chinade Rowe told the court she was aware of her brother's hair loss and had helped massage his special shampoo, which she referred to as "acid", into his scalp.
When asked by prosecutor Luke Ponte if she had come to court to lie for her brother, she replied: "Absolutely not".
Mr Ponte asked: "Why did you have to massage the shampoo into his head? Why was he unable to do that himself?"
"Because I had better massage techniques and I could do it better for him," she said.
"If you try and massage your head yourself it's not the same as someone doing it for you."
Mr Collins, of Broxbourne, Hertfordshire, denies five counts of grievous bodily harm (GBH) with intent, and nine counts of actual bodily harm (ABH) against 14 people.
Co-accused Andre Phoenix, of Clyde Road, Tottenham, north London, denies four counts of GBH and two counts of ABH.
The trial continues.