Keeping cash idle in a cash account offers a margin of safety during periods of deflation. If it's large enough, it might help the company cover the expenses of daily operations for the duration of the deflationary period.
Even with the account's cash increasing in value it is still experiencing a dollar depletion as it's being utilized. It just makes sense that anyone would want to at least slow the process as much as possible especially if there is little or no source of replenishment like revenues from sales.
A repositioning of cash in the cash account might help. This could be done by purchasing some very liquid, short-term, low-risk or no-risk investments that would serve as cash generators for a small contribution to the cash account when the funds become available to replenish it.
Money market accounts would be a likely place to be investing funds for this purpose. These are where investment banks put their money between deals and are also used by hedge funds if a market downturn seems imminent.
An investor can invest in money market instruments, which include certificates of deposit, commercial paper, US Treasuries, banker's acceptances, and repurchase agreements. The income is small but the risk is low and dollars with increasing value will be added to a cash account to slow its depletion. Anyone contemplating this should definitely look before they leap to make sure they choose investments that are suitable for them. No one would like to need cash quickly and have no money market investments coming due soon enough.