More than yearly cleanings?

I recently picked up a hospital and 2 hotels. All 3 only want done once per year. Is anyone having success approaching these large buildings about a semiannual or bimonthly cleaning. Doing the insides maybe once per year?

I do a holiday inn monthly -all the common areas, lobby, entrances, restaurant and 1x a year all outsides (3 stories). try to get them to do common areas more frequently possibly. The medical building i do is 2x year. Harder to get them to do more often, I think youd have more luck w/ hotel, maybe give a small discount for more frequent cleanings.