You can enter Mexico with a valid US visa - the only visa requirement must be in place at the time of your entry and exit, no more requirements are $ . So no overnight stays in the US are required . Moreover, secretly I will tell that getting a Mexican visa by citizens of Kazakhstan is very difficult - because we must go to Moscow, independently submit documents, independently take them, somewhere at this time to live and so on . Therefore, the easiest way to get to Mexico is using the US visa . Have a good trip!