Can you Build Muscle with ‘X’ exercise?

Yes. Whatever exercise you were thinking of when you asked this question yes. Stop limiting your mindset to “maybe” or “it’s not as effective”. You know what’s not effective at building muscle? Your attitude. It may require some modifications, additional weights, bands, accommodating resistance but it can and will build muscle but it’s on you to discover how. As an example people will argue that Pistol Squats aren’t an effective or efficient exercise to build massive legs since the stabilizer muscles that help you with the balancing portion would give out well before the quads and glutes would ,thus they believe this limits your chances of getting a pump or occurring enough local muscle fatigue to build muscle. However although a valid argument it does not mean the Pistol Squat won’t build muscle mass. In fact if we take this same movement, load it up with a weighted vest or backpack and increase our stability by holding onto two chairs, wall or objects to assist our balance then we can really drive the muscles to failure without worrying about our balance giving out before our quads. The catch is you have to use a light of a grip on whatever you’re assisting yourself with as possible, we want to get the most out of performing the movement so we have to limit the assistance to really force our muscles to reach the growth we desire.