Home owners, don't use bleach to keep your condensate drain clear, and techs, stop recommending it.
Here's a quote from the Rheem/Ruud _HSL air handler installation instructions
"12.2 INDOOR COIL - DRAIN PAN - DRAIN LINE
Inspect the indoor coil once each year for cleanliness and clean as necessary. In some cases, it may be necessary to remove the filter and check the return side of the coil with a mirror and flashlight.
IMPORTANT: Do not use caustic household drain cleaners, such as bleach, in the condensate pan or near the indoor coil. Drain cleaners will quickly damage the indoor coil."