Moving rests in \drums context

[Cameron Horsburgh]

Hi folks,

I am typesetting a part for a drum kit. The staff consists of two 
drumVoices.

In several locations both voices are resting, so I want to print one 
rest instead of two. In a \notes context, I would probably do something 
like this:

<<
{e4 e b4\rest e} \\
{g4 g s g}
>>

The rest would be printed by the top voice, and the bottom voice would 
have a spacer note.

In a \drums context, this doesn't seem to work. If I try

<<
{hh4 hh tomml4\rest hh} \\
{bd4 bd s bd}
>>

I get a message telling me there's an unexpected REST when a drum note 
is expected.

Is there a way to use this function in a drums context? Or do I need to 
set the rest manually?

Thanks in advance,

Cameron