toto,
i also use j&j mosquito lotion, mosquito patch, and recently bought the electric mosquito repellent. it worked most of the time, n it said it's safe for children. also got the one using sound to repell mozzie but the sound irritates both mozzie n me, so i stop using it.
btw the dermalife mosquito patch, after some time of storing it (coz buy in bulk), it's not so sticky anymore, kkeep falling off mybb's clothes.