My BB is trying not to use diapers in day time now. We have the training in summer but not that successful. It is because we always remind BB to have vv which made BB rely on us. Then, we are suggested not to remind even BB may vv everywhere. Finally BB "perform" good. (but, in winter, BB still will vv everywhere sometimes)
So, maybe you can buy more trousers first and then just let your BB take its "own job". Hahaa... of course, no blame (you know they always try their best even sometimes they don't perform "good". We should be proud of them, right? ) and you have to wash trousers + wipe floor frequently.
By the way, if possible (not that urgent), I think it is better to have the training in summer time.