Chalet Fresh,
The reason many people don’t get results, is they don’t use the correct programs. Now, the link you showed is a cheap TENS, which will not allow you to train properly. I would suggest a unit that has the EMS parameter programmed in different protocols already labeled in the menus of the unit.
As in voluntary training, different EMS training protocols have to be employed for different goals you’d like to obtain. Take a look at the following table, to get a glimpse of the different protocols that you could use. In voluntary exercise you wouldn’t do 1 rep at 95% of 1RM exercises to pursue the same training goals that you would pursue with 8 rep at 70%. There are about half a dozen parameters to set; getting a decent machine with ready made protocols takes you half way through it. The remaining other half of the way, since you are new to the field, is to work with a coach who is familiar with EMS.