Alex wrote about teaching unmotivated students.
Well, I don't suppose anyone's likely to learn anything very much in
the absence of some kind of motivation. The term 'motivation', of
course, covers a whole load of different phenomena, but one
distinction seems particularly relevant here:

You can be motivated, or not, to learn something (e.g. a language) in
a general sense, and you can be motivated, or not, by the particular
learning task that you're involved in at the moment - which might be
self-imposed, or might be imposed by someone else, such as a teacher.
These two types of motivation are in principle independent of each other.

Silent Way seems to be particularly effective in engendering a strong
sense of the 'here-and-now' type of motivation (though probably not
for everyone). Whether that transfers into the 'general' type of
motivation is another matter, of course.

Alex also mentioned the factor of class size. A class of ten is
probably preferable to a class of thirty for most purposes (though it
might depend on who the ten are, perhaps?) I think a Silent Way
teacher would typically work successively with small sub-groups of the
class, perhaps even with individuals, while the rest of the class are
apparently onlookers or observers, but nevertheless all working
privately and no doubt making as much progress as the ostensibly
active members - or even more progress, maybe.

Jonathan