Delay sprays are of limited use. they work by numbing the outer skin of your penis and reduce sensation in it thus dealaying your ejaculation, but it can also trigger numbing of her private parts and she might not feel sensation, bringing you back to square one. The best way in my opinion is to use condoms that have this thick delaying liquid in them, when you wear them, it will numb your penis a bit helping you to delay and she will not feel any loss of sensation in her private parts. One well known brand is Durex Poerforma condoms. If you dont find it in shops, look online. Try avoiding cheaper unknown brands.

Creams, lotions, sprays, pills are all useless.

Anything applied to the penis numbs only the skin of the penis, which is touch sensitive.

When your penis is sliding in and out of your partner's vagina, what makes you come is the squeezing action on the head and shaft of your penis, which is pressure sensitive. Pressure sensitivity cannot be numbed by cream and you will come just as quick.

Save your money and learn orgasm control. Use PC muscle relaxation and the other methods.