Both perpetrator and victim must exercise great caution when sleaze is on the table because it actually takes real skill to implement "legal" sleaze. When it's legal, I respect and use sleaze as often as the next guy. But I've often found alleged "sleaze" was actually a clear rules violation in progress. When someone tries to pull sleaze, any sleaze, pay close attention to the rules to make sure they are doing it "right." If they are doing it right, make 'em pay for it with "counter sleaze."
For example, while the "break to route with MG" sequence above is possible, there are numerous rule complications - especially with routing - that get in the way of a happy ending. To begin, per A10.41 you must be within LOS and normal range of an armed, unbroken, known enemy unit to voluntarily break. Now, if that's the case, why not just fire the MG at those enemy units rather than dismantle it? Anyway, assuming that is the case, once you break, per A10.51, you cannot route toward a known armed enemy unit. So, you cannot route towards the very same enemy that enabled your voluntary break! Where are you going? You must designate the nearest woods or building as your target and go that way, unless of course it's closer to the enemy. You can ignore your own building (but not woods patch) for that, but once you enter woods or building hex you must stop unless you can enter another woods or building hex. That rule (see A10.51) is often overlooked. It means that once you enter woods/building you cannot run around freely - even if out of enemy LOS - unless you are moving from building/woods into another building/woods. All of those hexes cost 2MF, so you're not going very far. Therefore, in the example above, close attention to route rules will foreclose many, many options making it extremely difficult to actually benefit from that scheme.
The same holds for most attempts at sleaze; it often crumbles under scrutiny. Of course, there are cases where sleaze works, but often at a price. I can use my AFV to "sleaze freeze" the other guy with certainty, but there are many things he can do to mitigate such as: fire at the AFV before it enters to lay down residual FP for the infantry he knows will follow, hit me with reaction fire or street fighting, get a better chance at ambush in CC, etc.
Rules knowledge is your best defense against sleaze, real and imagined.