The chaotic evolution in the combustion of CO in a well-stirred now reactor is controlled experimentally using a modified form of the simple proportional feedback (SPF) algorithm. An unstable period-1 oscillation is stabilized through the imposition of small, appropriate perturbations which are calculated from the observed experimental response of the system and do not require any information concerning the reaction mechanism. It is observed that the algorithm is significantly more efficient if these perturbations are applied for only a fraction of the oscillatory period. A similar observation is made from a numerical study of a model for the H-2 + O-2 reaction, and it is shown that this arises because the perturbations shift the system significantly from the attractor of the unperturbed system. The duration of the perturbation in each cycle then becomes a second control parameter and effects a higher-dimensional control algorithm in a simple manner appropriate to experimental implementation for such demanding systems. The control strategy is seen to be sufficiently robust to operate even though the system shows a marked drift over the course of the experiment. Some comments concerning strategies for the optimal implementation of SPF methods are then made.