The Zen center I sat at for a while when I lived in Dallas, didn't do any proselytizing that I noticed. As I understand is the general practice, if you tell the Roshi what purpose you're meditating for, he'll assign you an appropriate practice. If you're seeking "bompu Zen" -- i.e., purely material benefits like concentration and willpower enhancement, you'll generally be assigned a practice like counting your breaths. Enlightenment seekers are more likely to be assigned following the breath, a koan, or shikan-taza.