I don't agree with your advice. Checkboxes are designed to handle boolean values and a checkbox is perfectly suited for this situation, think of common "do you accept these terms" checkboxes. Handling a checkbox with CGI is as easy as the following...

my $boolean = $cgi->param('boolean') || 0;
# or better:
my $boolean = $cgi->param('boolean') ? 1 : 0;
# etc
[download]

Afterall, even if a true/false pair of radio buttons were used, user input cannot be trusted and the parameter would have to go through the same / similar process to above.