You can invest in CETES directly through https://www.cetesdirecto.com/SSOSVD_wls/ The CETE is more like a US Treasury T-Bill with terms of 28, 90, 180 and 365 days. There's lots of rules and requirements in order to open an online account and once open you are limited deposits of up to to 3,000 UDIs per month. https://coinmill.com/MXV_calculator.html#MXV=3000
Right now, that is about 21,400 pesos. There is a way to make larger deposits, but you have to go to a Bienestar branch in Tlaquepaque with a lot more paperwork and an e.firma from SAT. A CEDE is more akin to a certificate of deposit and will pay different rates for based on the amount. At Multiva you need over $1 million pesos to get the highest rate.