Does madhy have a smell, especially if the smell is strange, and what is the ruling concerning the white, viscous fluid that has the characteristics of madhy, but its time of emission is not precisely known?

As long as you are certain that what is coming out is madhy (pre-seminal fluid) because its characteristic is that of madhy, then wudu' (ablution) is obligatory after it, and the body and clothes must be purified. Madhy is a thin, white fluid that is discharged when desire subsides without actual arousal, and its discharge is not followed by fatigue in the body. One may not even feel its exit, and it is more common in women than in men. So, if the fluid you saw has this characteristic, then it is madhy, whether it has an odor or not.