I used to go out to the garden as often as I could take pepsi outside with me , and also after every time she had her food I would let her outside , if she messed I would just pick her up take her out and just say to her go pee pee , .
Thats the best way take them outside and clean up.
My word to pepsi was always peepee , it took her a while , but when she got the idea she loved the attention she got afterwards and had me up to the door ever 10mins

She's 9 now and I still open the door to the garden and say go peepee its funny how we don't drop silly habits.
Happy training