Apparatuses and methods for electrohydraulic generation of shockwaves at a rate of between 10 Hz and 5 MHz, and/or that permit a user to view a region of a patient comprising target cells during application of generated shockwaves to the region. Methods of applying electro-hydraulically generated shockwaves to target tissues (e.g., for reducing the appearance of tattoos, treatment or reduction of certain conditions and/or maladies).